SMC Networks 6.20 manual Defining Filter Formulas

--Date the data arrives --Time the data arrives --Greater than --Less than

--Greater than or Equal to --Less than or Equal to --Equal

--Unequal

--Number represented in decimal digits, within the range of a 4-byte unsigned integer.

--Eight digits representing a date.

--Eight digits representing a time, in 24 hour format

ComplexExpression

--Value of the data

DEFINING FILTER FORMULAS

Defining Filter Formulas

Filters may be defined for any log process. A filter sets the conditions that determine if data received by the Log Manager will be saved into the log database. A filter is defined in the Filter field of the Log Information dialog box (i.e., the dialog box opened when you create or edit a log process). If no filter is defined, then all the data received is automatically logged.

Filter Formula

The filter formula uses Backus-Naur Form (BNF) as follows:

Filter::=SimpleExpression

ComplexExpression

<NULL> -- Nothing

SimpleExpression::=Variable rel_op Value

Variable::= "VALUE"

"DATE"

"TIME"

rel_op::= ">" "<" ">=" "<=" "==" "!="

Value::=<INTEGER VALUE>

<yymmdd>

<hhmmss>

ComplexExpression::=

"(" SimpleExpression ")"

"(" ComplexExpression ")" ComplexExpression logic_op logic_op::="AND""OR"

7-7